Ammonia recovery device

Abstract

The utility model provides an ammonia recovery device. The ammonia recovery device comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower which are sequentially connected, the first absorption tower is connected with an induced draft fan through a pipeline; a first bubble cap type tray, a second bubble cap type tray and a third bubble cap type tray are sequentially arranged at the upper part of the fourth absorption tower; the upper part of the third bubble cap type tray is connected with a water inlet pipe; the first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower are internally and respectively provided with a filler layer and a groove disc gas-liquid distributor. According to the ammonia recovery tower, old equipment is used for transformation, the operation effect is good, design indexes can be achieved, many defects of a glass fiber reinforced plastic ammonia recovery tower do not exist, the construction cost can be greatly reduced, the construction period can be greatly shortened, and up-to-standard emission of dry ammonium tail gas and carbonized and crystallized flash air ammonia is achieved early; the comprehensive purposes of reducing the ammonia consumption of the system, reducing the pollution of the produced waste gas to the atmospheric environment and relieving the environmental protection pressure of companies are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of ammonia recovery towers, and in particular relates to an ammonia recovery device. Background Art

[0002] The soda ash industry is an important chemical raw material industry, but at the same time it causes serious pollution and is difficult to reduce emissions. The soda ash industry must take a green and clean development path to achieve rapid and good development.

[0003] Most of the current ammonia recovery devices are composed of FRP cylinders, internal spherical and corrugated plastics, low-pressure fans, FRP pipes and other components. The tower height is limited, the ammonia recovery effect is poor, and the single tower has limited waste gas treatment capacity. Regular maintenance, inspection, and replacement of internal fillers and pipe materials are required because they are made of FRP. There are many leakage points in daily use, which can easily cause external pollution.

[0004] Publication No. CN214653678U discloses an ammonia recovery process device, including a wastewater storage device, the wastewater storage device is connected to an atmospheric pressure ammonia evaporation tower through a pipeline, the bottom of the atmospheric pressure ammonia evaporation tower is connected to a negative pressure ammonia evaporation tower through a pipeline 1, the atmospheric pressure ammonia evaporation tower is connected to a heating device 1, and the negative pressure ammonia evaporation tower is connected to a heating device 2; one side of the atmospheric pressure ammonia evaporation tower is connected to a reheating device through a pipeline 2, the reheating device is connected to the negative pressure ammonia evaporation tower, the reheating device is connected to an ammonia storage tank through a pipeline 3, and a cooling device is provided on the pipeline 3; a wastewater treatment device is provided at the bottom of the negative pressure ammonia evaporation tower; the utility model produces ammonia with a concentration of 18-20%, compared with the traditional process, the steam consumption can be reduced by 30-40%, the traditional process can be transformed, the energy consumption can be greatly reduced, the ammonia content in the acid gas at the top of the tower can be greatly reduced, and the ammonia yield can be improved. The application structure is relatively complex, and the process flow cannot completely remove the ammonia content, the ammonia recovery effect is poor, and the waste treatment capacity is limited.

[0005] Since the cost of building a new ammonia recovery tower is high, a new site and new equipment design are required, the construction period is long, the cost is high, and the economy is poor; the three existing uncooled towers have been idle after being shut down and can be transformed and used as ammonia recovery towers. This can greatly reduce the construction cost and construction period, and achieve the emission of dry ammonia tail gas and carbonization and crystallization ammonia in compliance with standards as soon as possible. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide an ammonia recovery device in view of the deficiencies of the prior art, aiming at improving the recovery efficiency and reducing the cost.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0008] An ammonia recovery device comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower which are connected in sequence and obtained by remodeling an old uncooled tower; the first absorption tower is connected to an induced draft fan through a pipeline; the fourth absorption tower is provided with a first bubble-cap tray, a second bubble-cap tray and a third bubble-cap tray which are connected in sequence; the upper part of the third bubble-cap tray is connected with a water inlet pipe for liquid sealing; the first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower are respectively provided with a packing layer and a trough-plate gas-liquid distributor.

[0009] Preferably, a first packing layer is provided in the first absorption tower, on which a first trough plate gas-liquid distributor is provided; a second packing layer is provided in the second absorption tower, on which a second trough plate gas-liquid distributor is provided; a third packing layer is provided in the third absorption tower, on which a third trough plate gas-liquid distributor is provided; a third packing layer is provided in the third absorption tower, on which a third trough plate gas-liquid distributor is provided; a fourth packing layer is provided in the fourth absorption tower, on which a fourth trough plate gas-liquid distributor is provided.

[0010] Preferably, a first liquid phase collecting and extracting component is provided at the lower part of the third packing layer in the third absorption tower; and a second liquid phase collecting and extracting component is provided at the lower part of the fourth packing layer in the fourth absorption tower.

[0011] Preferably, an induced draft fan inlet pipe is installed at the air inlet of the induced draft fan, and an induced draft fan outlet pipe is installed at the induced draft fan outlet, and a first air inlet pipe, a second air inlet pipe and a third air inlet pipe are connected and arranged, and one end of the first air inlet pipe, the second air inlet pipe and the third air inlet pipe away from the induced draft fan outlet pipe is connected to a fin tangential air inlet distribution assembly in the first absorption tower.

[0012] Preferably, the first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower are respectively connected in parallel with a first heat exchanger, a second heat exchanger, a third heat exchanger and a fourth heat exchanger outside.

[0013] Preferably, the first bubble-cap tray, the second bubble-cap tray and the third bubble-cap tray are respectively provided with a first multi-channel baffle demister, a second multi-channel baffle demister and a third multi-channel baffle demister.

[0014] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0015] The utility model divides the absorption tower into five sections. Sections 1 to 4 are provided with high-efficiency structured fillers and special distributors. Sections 1 and 2 from bottom to top are for circulation absorption. Two heat exchangers are provided outside the tower to circulate water. Most of the ammonia is absorbed in the circulation cooling absorption. The ammonia water in the tower bottom is discharged after reaching a certain concentration. Sections 3 and 4 of the filler sections adopt separate circulation absorption, and each is provided with a heat exchanger outside the tower. A three-layer high-efficiency absorption special bubble cap tray is provided at the top of the tower. The tray has the characteristics of large flux and small pressure drop, and its pressure drop is about 2 / 3 of that of the standard bubble cap. Fresh water at the top of the tower performs liquid-sealed washing and absorption on the tail gas, so that the tail gas is discharged in a qualified manner. The system has the advantages of simple process flow, mature and stable technology, simple and easy operation, high ammonia recovery rate, and low tail gas emission.

[0016] This application utilizes old equipment for transformation, has good operation effect, can achieve design indicators, and does not have many disadvantages of glass fiber reinforced plastic ammonia recovery tower. The parts that need to be modified are redesigned according to actual conditions, which can greatly reduce construction costs and construction periods, and achieve the standard emission of dry ammonium tail gas and carbonization and crystallization ammonia as soon as possible; to achieve the comprehensive purpose of reducing system ammonia consumption, reducing the pollution of production waste gas to the atmospheric environment, and alleviating the company's environmental protection pressure. The advantages of this system are high ammonia recovery rate, low emissions, and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present utility model;

[0019] Among them, 1. the first absorption tower; 11. the first packing layer; 12. the first trough gas-liquid distributor; 13. the first heat exchanger; 14. the first heat exchanger pipeline; 2. the second absorption tower; 21. the second packing layer; 22. the second trough gas-liquid distributor; 23. the second heat exchanger; 24. the second heat exchanger pipeline; 3. the third absorption tower; 31. the third packing layer; 32. the third trough gas-liquid distributor; 33. the first liquid phase collection and extraction component; 34. the third heat exchanger; 35. the third heat exchanger pipeline; 4. the fourth absorption tower; 41. the fourth packing layer; 42. the fourth trough Plate gas-liquid distributor; 43, second liquid phase collection and extraction component; 44, fourth heat exchanger; 45, fourth heat exchanger pipeline; 5, first bubble-cap type tray; 51, first multi-channel baffle demister; 6, second bubble-cap type tray; 61, second multi-channel baffle demister; 7, third bubble-cap type tray; 71, third multi-channel baffle demister; 8, water inlet pipe; 9, induced draft fan; 91, induced draft fan air inlet pipe; 92, induced draft fan air outlet pipe; 93, first air inlet pipe; 94, second air inlet pipe; 95, third air inlet pipe; 10, fin tangential type air inlet distribution component. DETAILED DESCRIPTION

[0020] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0021] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0022] Embodiment 1: An ammonia recovery device is provided, comprising a first absorption tower 1, a second absorption tower 2, a third absorption tower 3 and a fourth absorption tower 4 which are modified from an old uncooled tower and whose internal spaces are sequentially connected; the first absorption tower 1 and the second absorption tower 2 are cyclic absorption, and the absorption liquid circulation volume is 250m 3 / h; most of the ammonia is absorbed in the circulating cooling absorption. The third absorption tower 3 and the fourth absorption tower 4 adopt separate circulating absorption. The circulation volume of the absorption liquid of the third absorption tower 3 is 180m 3 / h, the fourth absorption tower 4, the filling absorption liquid circulation volume is 40m 3 / h; the first absorption tower 1 is connected to the induced draft fan 9 through a pipeline; the first bubble-cap tray 5, the second bubble-cap tray 6 and the third bubble-cap tray 7 are arranged in sequence on the upper part of the fourth absorption tower 4; the upper part of the third bubble-cap tray 7 is connected to the water inlet pipe 8; the fresh water on the top of the tower performs liquid-sealed washing and absorption on the tail gas to ensure that the tail gas is discharged in a qualified manner; the first absorption tower 1, the second absorption tower 2, the third absorption tower 3 and the fourth absorption tower 4 are respectively provided with a packing layer and a trough-plate gas-liquid distributor.

[0023] Preferably, the first absorption tower 1 is provided with a first packing layer 11, on which a first trough plate gas-liquid distributor 12 is provided; the second absorption tower 2 is provided with a second packing layer 21, on which a second trough plate gas-liquid distributor 22 is provided; the first packing layer 11 and the second packing layer 21 are each 4 meters of 250PLUS plate corrugated metal structured packing, the liquid circulation volume in this area is the largest, and the relative load is the highest in the whole tower, so a low pressure drop, high efficiency 250PLUS structured packing is selected; the third absorption tower 3 is provided with a third packing layer 31, on which a third trough plate gas-liquid distributor 32 is provided; The third absorption tower 3 is provided with a third packing layer 31, on which a third trough plate gas-liquid distributor 32 is provided; the fourth absorption tower 4 is provided with a fourth packing layer 41, on which a fourth trough plate gas-liquid distributor 42 is provided; the third packing layer 31 has a relatively small liquid phase load, and in order to ensure the absorption efficiency and save costs, considering that the temperature of this section is relatively low, a 4-meter 250Y plate corrugated plastic PP structured packing is used; the fourth packing layer 41 is a key part to ensure exhaust gas emission, so a relatively high-efficiency 350PLUS metal structured packing is used, which can ensure efficiency and maintain a reasonable pressure drop. The first trough plate gas-liquid distributor 12, the second trough plate gas-liquid distributor 22, the third trough plate gas-liquid distributor 32 and the fourth trough plate gas-liquid distributor 42 ensure uniform gas-liquid distribution in the tower and also ensure reasonable low pressure drop requirements.

[0024] Preferably, a first liquid phase collecting and producing component 33 is provided at the lower part of the third packing layer 31 in the third absorption tower 3; a second liquid phase collecting and producing component 43 is provided at the lower part of the fourth packing layer 41 in the fourth absorption tower 4. The first liquid phase collecting and producing component 33 and the second liquid phase collecting and producing component 43 ensure smooth production of circulating liquid while meeting the low pressure drop requirement.

[0025] Preferably, a fin tangential air inlet distribution component 10 is provided at the bottom of the first absorption tower 1, and the fin tangential air inlet distribution component 10 is connected to the first air inlet pipe 93, the second air inlet pipe 94 and the third air inlet pipe 95, so as to ensure that the gas phase has a better distribution before entering the packing section, thereby enhancing the overall absorption efficiency of the packing section.

[0026] Preferably, the first air inlet pipe 93 , the second air inlet pipe 94 and the third air inlet pipe 95 are connected to an induced draft fan air outlet pipe 92 of the induced draft fan 9 , and the induced draft fan 9 is also connected to an induced draft fan air inlet pipe 91 .

[0027] Preferably, the first absorption tower 1, the second absorption tower 2, the third absorption tower 3 and the fourth absorption tower 4 are respectively connected in parallel with the first heat exchanger 13, the second heat exchanger 23, the third heat exchanger 34 and the fourth heat exchanger 44, which are respectively connected to the absorption towers through the first heat exchanger pipeline 14, the second heat exchanger pipeline 24, the third heat exchanger pipeline 35 and the fourth heat exchanger pipeline 45; the first heat exchanger 13 and the second heat exchanger 23 realize the cyclic absorption of the first two sections from bottom to top, most of the ammonia is absorbed in the cyclic cooling absorption, and the ammonia water in the tower bottom is discharged after reaching a certain concentration; the third heat exchanger 34 and the fourth heat exchanger 44 realize the separate cyclic absorption of the last two sections from bottom to top.

[0028] Preferably, the first bubble-cap type tower tray 5, the second bubble-cap type tower tray 6 and the third bubble-cap type tower tray 7 are respectively provided with a first multi-channel baffle demister 51, a second multi-channel baffle demister 61 and a third multi-channel baffle demister 71, which are used to remove the foam in the water circulation step by step and improve the liquid-seal washing absorption effect of the fresh water at the top of the tower on the exhaust gas.

[0029] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0030] The utility model divides the absorption tower into five sections. Sections 1 to 4 are provided with high-efficiency structured fillers and special distributors. Sections 1 and 2 from bottom to top are for circulation absorption. Two heat exchangers are provided outside the tower to circulate water. Most of the ammonia is absorbed in the circulation cooling absorption. The ammonia water in the tower bottom is discharged after reaching a certain concentration. Sections 3 and 4 of the filler sections adopt separate circulation absorption, and each is provided with a heat exchanger outside the tower. A three-layer high-efficiency absorption special bubble cap tray is provided at the top of the tower. The tray has the characteristics of large flux and small pressure drop, and its pressure drop is about 2 / 3 of that of the standard bubble cap. Fresh water at the top of the tower performs liquid-sealed washing and absorption on the tail gas, so that the tail gas is discharged in a qualified manner. The system has the advantages of simple process flow, mature and stable technology, simple and easy operation, high ammonia recovery rate, and low tail gas emission.

[0031] This application uses the old equipment uncooled tower to transform. The absorption tower is divided into five sections, with good operation effect, can reach the design index, and does not have many disadvantages of glass fiber reinforced plastic ammonia recovery tower. The parts that need to be modified are redesigned according to the actual situation, which can greatly reduce the construction cost and construction period, and achieve the standard emission of dry ammonium tail gas and carbonization and crystallization ammonia as soon as possible; to achieve the comprehensive purpose of reducing system ammonia consumption, reducing the pollution of production waste gas to the atmospheric environment, and alleviating the company's environmental protection pressure. The advantages of this system are high ammonia recovery rate, low emissions and low energy consumption.

[0032] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the utility model can be improved in only one or several aspects, without having to solve all the technical problems listed in the prior art or background technology at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be used as a limitation on the claim.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the preferred implementation scheme of the utility model and are not limiting. Other modifications or equivalent substitutions made to the technical scheme of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical scheme of the utility model.

Claims

1. An ammonia recovery device, characterized in that: The tower is reconstructed from an old uncooled tower, comprising a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, the internal spaces of which are sequentially connected; the first absorption tower is connected to an induced draft fan through a pipeline; the upper portion of the fourth absorption tower is provided with a first bubble-cap type tray, a second bubble-cap type tray and a third bubble-cap type tray, the internal spaces of which are sequentially connected; the upper portion of the third bubble-cap type tray is connected with a water inlet pipe for liquid sealing; the first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower are respectively provided with a packing layer and a trough-plate gas-liquid distributor.

2. The ammonia recovery device according to claim 1, characterized in that: The first absorption tower is provided with a first packing layer, on which a first trough plate gas-liquid distributor is arranged; the second absorption tower is provided with a second packing layer, on which a second trough plate gas-liquid distributor is arranged; the third absorption tower is provided with a third packing layer, on which a third trough plate gas-liquid distributor is arranged; the fourth absorption tower is provided with a fourth packing layer, on which a fourth trough plate gas-liquid distributor is arranged.

3. The ammonia recovery device according to claim 2, characterized in that: A first liquid phase collecting and extracting component is arranged at the lower part of the third packing layer in the third absorption tower; and a second liquid phase collecting and extracting component is arranged at the lower part of the fourth packing layer in the fourth absorption tower.

4. The ammonia recovery device according to claim 1, characterized in that: The air inlet of the induced draft fan is installed with an induced draft fan air inlet pipe, the air outlet of the induced draft fan is installed with an induced draft fan air outlet pipe, and a first air inlet pipe, a second air inlet pipe and a third air inlet pipe are connected and arranged, and one end of the first air inlet pipe, the second air inlet pipe and the third air inlet pipe away from the induced draft fan air outlet pipe is connected to a fin tangential air inlet distribution assembly in the first absorption tower.

5. The ammonia recovery device according to claim 1, characterized in that: The first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower are respectively connected in parallel with a first heat exchanger, a second heat exchanger, a third heat exchanger and a fourth heat exchanger outside the first absorption tower, the second absorption tower, the third absorption tower and the fourth absorption tower.

6. The ammonia recovery device according to claim 1, characterized in that: The first bubble-cap tray, the second bubble-cap tray and the third bubble-cap tray are respectively provided with a first multi-channel baffle demister, a second multi-channel baffle demister and a third multi-channel baffle demister.

Images